Rotary digging head



Jan. 25, 1966 1.. GATES ROTARY DIGGING HEAD 3 Sheets-Sheet 1 Filed July22, 1963 INV EN TOR. .566 6d 2695 Jan. 25, 1966 L. GATES ROTARY DIGGINGHEAD 3 Sheets-Sheet 2 Filed July 22, 1963 Jan. 25, 1966 GATES ROTARYDIGGING HEAD 5 Sheets-Sheet 5 Filed July 22, 1963 United States Patent3,230,647 ROTARY DIGGING HEAD Lee Gates, South San Francisco, Calif.(121 S. Magnolia, Millbrae, Calif.) Filed July 22, 1963, Ser. No.296,671 1 Claim. (Cl. 37190) This invention relates in general to earthdigging or excavating machines, and particularly to one of the typewhich employs a rotary digging head. Such head is of the type whichincludes a number of circumferentially spaced earth digging andreceiving pockets which become filled as the head rotates and which thendischarge, with further rotation of the head, onto a carry-off conveyormounted in connection with the head-supporting structure.

It is a major object of this invention to provide automaticallyfunctioning means to successively discharge the earth from the loadedpockets of the rotary head and onto the carry-off conveyor, and whichmeans function equally well regardless of the speed of rotation of suchhead. 4

The rotary head of this invention, and which includes the earth diggingand receiving pockets, is mounted on a boom on which the carry-offconveyor is supported; it being a further object of the invention toarrange and mount the head on the boom so that the direction of rotationof the head relative to the boom may be easily reversed, while the sametime the pockets will always discharge onto the one carry-off conveyor.

Another object of the invention is to provide head rotating mechanismwhich includes an electric drive motor within the head, so that onlyflexible and readily trained current supplying wires project from thehead and along the boom to a source of current.

Each earth digging and receiving pocket includes a push-out gate whichis moved to eject the earth, at the proper point, by the rotative actionof the head; a further object of the invention being to so arrange thegates on the pockets that when pockets reach a discharging positionrelative to the carry-off conveyor, only a minimum of power is requiredto move the gates to their full ejecting position.

A further object of the invention is to provide a rotary digging headwhich is designed for ease and economy of manufacture.

A still further object of the invention is to provide a practical,reliable, and durable rotary digging head, and one which is exceedinglyeffective for the purpose for which it is designed.

These objects are accomplished by means of such structure and relativearrangement of parts as will fully appear by a perusal of the followingspecification and claim.

In the drawings:

FIG. 1 is a side elevation of the improved rotary digging head asmounted on a supporting boom.

FIG. 2 is an enlarged sectional elevation, taken on line 2-2 of FIG. 3

FIG. 3 is a transverse section, taken substantially on line 33 of FIG.2.

FIG. 4 is a further enlarged fragmentary transverse section, taken online 4-4 of FIG. 2.

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Referring now more particularly to the drawings and to the characters ofreference marked thereon, the rotary digging head 1, hereinafterdescribed in detail, is designed to be supported from a suitable boom 2;such boom including transversely spaced plates 3 at its outer endbetween which the head 1 is disposed. The boom 2 is mounted on a pusherimplement (not shown), and is vertically swingably adjustable in anyconventional manner.

The head 1 comprises a central tubular shaft 4 extending between andturnably mounted in the plates 3. Laterally out from said plates theends of said shaft are provided with splined or knurled portions 5 whichare releasably engaged by clamping collars 6. Each collar has a radialarm 7 projecting therefrom and which arm is adjustably secured to theadjacent plate 3 by bolts 8 engaging any selected ones of a row of holes9 in said plate concentric with the shaft 4. The purpose of thisspecific shaft mounting will be later described.

Disposed about the shaft 4 between the plates 3 and concentric with saidshaft are side discs 10 and 11; such discs being provided on theirlaterally outer sides with collars 12 turnably engaging the shaft 4.Fixed on the inner faces of the discs are internal gears 13 concentricwith the shaft 4 and engaged by pinions 14 fixed on a shaft 15 parallelto but offset from shaft 4; the shaft 15 being journaled in arms 16projecting from and rigid with said shaft 4, as clearly shown in FIG. 2.

A speed-reducing chain drive unit 17 connects shaft 15 with acountershaft 18 parallel to shaft 15 and also journaled in arm 16, and afurther speed-reducing chain drive unit 19 connects the countershaft 18and the axial shaft 20 of an electric motor 21. Such motor includes in abase 22 suitably secured in rigid relation with the shaft 4 and arms 16.The circuit wires 23 for the motor 21 extend through the tubular shaft 4to one end of the same, so that said wires may then extend along theboom 2 for connection to a source of electric current on the pushingimplement from which the boom projects. When the motor 21 is inoperation, the head 1 is thus rotated at a slow speed.

Projecting between the discs 10 and 11 at evenly spaced intervals aboutthe same are the back plates 24 of earth digging and receiving pockets25. These back plates 24 face and are concavely curved in the directiontoward which the head normally rotates; being generally radially of thehead. At the center of the arc of curvature of each plate 24, and whichcenter is adjacent the outer edges or rims of the discs 10 and 11, atransverse shaft 26 is journaled in said discs. A fiat gate 27, formingthe bottom of each pocket 25, extends radially from shaft 26 to therelated plate 24 to sweep the same from one end to the other uponrotation of the shaft 26. The extent of such sweeping movement islimited by a lip 28 on the plate 24 at the radially inner end thereofand at the other end by the projecting ends of transversely spaceddigging teeth 29 which extend from said plate 24 to a termination somedistance out from the periphery of the discs 10 and 11. The teeth areprovided with shanks 30 which are relatively narrow in a directioncircumferentially of the head 1, and which extend through a lip 31projecting back from the outer end of plate 24. The

shanks are curved to conform to the curvature of the plate 24 and engagethe back side of the same, being detachably secured thereto by bolts 32.

Projecting substantially at right angles from the back side of each gate27, and which is that side thereof opposite that engaged by the earth inthe related pocket 25, are transversely spaced elongated brackets 33 onthe outer end of each of which is a roller 34- disposed in thetransverse plane of the related arm 16. The outer portion of theperiphery of each arm forms a cam 35 positioned for engagement by eachrelated roller 34 as the latter, with the rotation of the head 1, movesdownwardly from the topmost position on the head 1; the arms 16 facinggenerally toward the boom 2, as shown in FIG. 2. Also, the cams 35 arearranged so that each gate 27, after the related rollers 34 first engagesaid cams, and which is when said gate is at its innermost position onthe corresponding plate 24 and is engaged by the lip 28 thereof, will beswung through its full stroke by the cam action.

It should be here noted that while the disc is permanently secured tothe back plates 24, as by welding, the disc 11 is detachable from saidplates 24 while being normally rigid therewith. This is accomplished bymeans of flanges 36 formed on the sides of the plates 24 opposite thedisc It the flanges engaging disc 11 and being secured thereto by bolts37, as best shown in FIG. 3.

In operation, the boom 2 is set so that the head 1 Will depend somedistance below the surface of the ground to be dug, as shown in FIG. 1.Upon the head 1 being rotated so that the side thereof facing away fromthe boom turns upwardly and with the boom gradually advancing, the teeth29 of the lowermost pocket 25 dig into and excavate the earth. As sodug, the earth presses upwardly into the corresponding pocket 25 and indoing so swings the gate. 27 of such pocket upwardly against the forceof gravity which up to this time has held said gate 27 down against theadjacent teeth. By the time the head 1 has rotated a relatively smallamount, or so that the teeth of said pocket leave the ground surface,the gate 27 of such pocket has been swung by the dug earth to its fullinward position, or so that said gate engages the adjacent lip 28. Inthis and the succeeding position of the pocket 25, the plate 24 becomesthe bottom, while the gate 27 forms the back thereof, as clearly shownin FIG. 2.

The pocket is thus substantially filled with earth and which it retainsuntil said pocket, with the rotation of the head, starts to move downfrom its topmost position on the head, and the related rollers 34 firstengage the earns 35. From then on down for a relatively short are ofrotation of the head, the gate 27 is swung or pushed, by the cam action,outwardly along the plate 24 to sweep the earth therefrom and empty therelated pocket 25, and until said gate 27 approaches a verticalposition. With this sweeping movement of the gate 27 and theaccompanying downward movement of the corresponding pocket 25, the earthas discharged from said pocket falls onto the adjacent end of a suitablydriven carry-off conveyor 38 mounted on the boom 2 between the sidesthereof.

It will be seen that the gates 27, when the related pockets reach aposition directly above the conveyor 38 when moving downwardly, aredisposedat an angle of substantially 90 degrees to the horizontal, andwhile at little more than 45 degrees to the horizontal before they reachthe 90-degree position, will allow loose dirt to spill from the pockets.This is an advantage in providing economy in operation, since a minimumof power is required in effecting the earth discharging operation.

When each emptied pocket 25, with the continued rotation of the head 1,moves below the conveyor 38, the related rollers 34 of said pocket leavethe cams 35. The gate 27 of the pocket then remains, by reason ofgravity action, in its outermost position until the pocket reachessubstantially its lowermost position on the roating head and earh as dugby the teeth 29 is swept into the pocket and causes the plate to begradually pushed up or toward the lip 28, as stated atthe outset of thisdescription of operation.

It will be noted, from the showing in FIG. 2, that the fixed earns 35occupy such definite position relative to the conveyor 38 as has beenfound to insure an efficient earth discharging action when handling acertain grade or condition of earth. If at any time, as when digging adifferent kind of earth or other material, it is found to beadvantageous to alter the setting of the cams 35 relative to theconveyor 38, his may be easily done by detaching the bolts 8 androtating the shaft 4 in one direction or the other, without alsorotating the head 1, until the desired new relationship of the cams 35to the said conveyor 38 is obtained. The bolts 8 are then engaged withother ones of the holes 9 in the plates 3.

It should also be noted that the rotary digging head 1 may be reversedin position relative to the boom 2, so that the head 1 at the bottomwill turn upwardly toward instead of away from the boom. In this case,the loaded pockets must move up past the conveyor before dischargingonto the same. Consequently, the cams 35 must be set accordingly and itmay be necessary to rotate the shaft 4 a greater amount than the row ofbolt holes 9 will accommodate. If this is the case, the clamping collars6 may be disengaged from the shaft 4 to allow the latter to be rotatedwhatever additional amount may be required to dispose the cams 35 in theproper position for engagement by the rollers 34 to exert a push-outaction on the related pocket gates 27 when the corresponding pockets 25move above the conveyor 38.

While the rotary digging head has been herein described for use in earthdigging and excavating, it is also useful ingravel loading, coal andiron ore mining, bank surfacing, and other similar operations.

From the foregoing description, it will be readily seen that there hasbeen produced such a device as substantially fulfills the objects of theinvention, as set forth herein.

While this specification sets forth in detail the present and preferredconstruction of the device, still in practice such deviations from suchdetail may be resorted to as do not form a departure from the spirit ofthe invention, as defined by the appended claim.

Having thus described the invention, the following is claimed as new anduseful and upon which Letters Patent is desired:

In an earth handling machine which embodies a supporting boom having acarry-01f conveyor thereon, a rotary digging head tu-rnably supportedfrom the boom and including a plurality of circumferentially spacedearth receiving pockets positioned to successively pass by the front endof the conveyor as the head rotates, each pocket including a fixedcurved back plate extending substantially radially of the head and aswingable push-out gate extending radially of the plate in engagement atits inner end therewith and pivoted at its outer end on the head forswinging movement between the inner and outer ends of the plate radiallyof the head, and means functioning with such rotation of the head toswing the gate from the inner to the outer end of said back plate wheneach such pocket reaches a position directly ahead of and on a levelabove the forward end of the conveyor; said gate swinging meanscomprising a relatively stationary cam, an element fixed with the gateand disposed for engagement by the cam upon the pocket reaching suchposition, said cam being common to the elements of all the pockets, anda stationary shaft mounted on the boom and on which shaft the head isturnable and from which shaft the cam projects in fixed relation; therebeing means to rotatably adjust the shaft on the boom including, withspaced side plates on the boom between which the shaft extends and bywhich it is supported, a releasable clamping collar on one end of theshaft outwardly of the adjacent side plate of the boom, a radial armprojecting from and rigid with the collar, and a bolt mounted in thearm, said adjacent side plate having a row of holes concentric with theshaft for selective engagement by the bolt.

References Cited by the Examiner UNITED STATES PATENTS Linga 3794 Crain.

Oldroyd 1989 Jespersen 37-189 Fogelberg 37190 Wuigk 37190 FOREIGNPATENTS France. Germany. Germany. Germany. Germany. Great Britain.

W. B. STONE, W. A. SMITH III, Assistant Examiners.

